Weekend Admission May Raise Risk of Death

Patients admitted for an emergency on a weekend are more likely to die in the hospital than those admitted on a weekday, researchers found.

Action Points

Note that in this large study of a 20% sample of U.S. community hospitals, the mortality rate was significantly higher for patients admitted for emergency care during the weekend compared with those admitted on weekdays.

Point out that this is a retrospective study and causative factors cannot be directly delineated, but since the results are consistent across multiple diagnostic categories, it is likely that a central factor is playing a role.

Patients admitted for an emergency on a weekend are more likely to die in the hospital than those admitted on a weekday, researchers found.

In an analysis of nearly 30 million patients, the inhospital mortality rate was significantly higher for those admitted on the weekend across a range of diagnoses (2.7% versus 2.3%, P<0.001), according to Rocco Ricciardi, MD, MPH, of Tufts University Medical School in Burlington, Mass., and colleagues.

In a multivariate analysis that adjusted for age, sex, race, income, payer, comorbidities, and hospital characteristics, weekend admission was associated with a 10.5% greater likelihood of dying (OR 1.10, 95% CI 1.10 to 1.11), the researchers reported in the May issue of Archives of Surgery.

"The consistency of the data across multiple diagnostic-related groups, patient demographics, comorbidities, and hospital characteristics indicates that a central and common factor is most likely responsible for the unfavorable outcomes," they wrote.

"Although the underlying mechanism of this finding is unknown, it is likely that factors such as differences in hospital staffing and services offered during the weekend compared with weekdays are causal and mutable."

Previous studies have identified this weekend effect on mortality, but many have focused on a narrow patient population. For example, past studies have found increased mortality on the weekends for patients in the intensive care unit and those with stroke or MI.

Ricciardi and his colleagues set out to explore whether such an effect could be seen across a wide range of diagnoses using data from the Nationwide Inpatient Sample, which approximates a 20% sample of community hospitals in the U.S.

The analysis included 29,991,621 patients (mean age 46) admitted for nonelective reasons from 2003 through 2007; 22.8% entered the hospital on the weekend.

Overall, 2.4% of the patients died before leaving the hospital, although those admitted on the weekend were more likely to do so.

There was significantly higher mortality on the weekends for 15 of 26 major diagnostic categories.

The odds of inhospital mortality were not significantly different between the week and the weekend for 10 other major diagnostic categories and were lower for one -- mental health disorders (OR 0.83, 95% CI 0.68 to 1.00, P=0.05).

It was not clear what could explain the higher mortality on the weekends, according to the authors, but comorbidities were accounted for and ruled out as an explanation.

"Thus, the admission day outcome differences implicate a common structural or process measure," Ricciardi and his colleagues wrote.

"This theory is substantiated by the lack of a significant difference in admission mortality rate for trauma or burn care. The evaluation and management of trauma and burns incorporate structured algorithms for care that likely reduced much of the variability in care practice that may be appreciated with other conditions," they continued.

"In addition, many patients who require care for trauma or burns present during the night and/or weekends; thus, clinical services for these conditions have been refined to account for these presentation patterns."

As previous studies have suggested, low staffing levels and reduced staff experience on the weekends could also explain the findings, according to the researchers.

They noted some limitations, including possible misclassification bias because of the administrative data used for the analysis, and the inability to adjust for disease severity at presentation.

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